Compositions, including a hydrogenated semidrying oil and methacrylate resin mixture as a lubricant



Patented Jan. 24, 1950 COMPOSITIONS, INCLUDING A HYDROGEN- A'IEDSEMIDRYING OIL AND METHACRY- LATE RESIN MIXTURE AS A LUBRICANT Victor A.Navikas, Lancaster, Pa., asslgnor to Armstrong Cork Company, Lancaster,Pa., a corporation of Pennsylvania No Drawing. Application December 31,1942, Serial No. 470,915

This invention relates to extrudable cork compositions and, moreparticularly, to an extrudable cork composition containing an improvedlubricant.

Cork compositions have been extruded heretofore in various forms for useas expansion joint materials, rods, discs, gaskets, and the like bymeans of a suitable extrusion device such as that disclosed in UnitedStates Patent No. 1,453,617, granted May 1, 1923, to William G. Bond. Insuch device, cork composition is placed at the entrance of an extrudingtube, and a reciprocable plunger is used to force the composition intothe tube and to compact it therein into the desired form. Heating andcooling zones are provided in the extrusion tube in order to set thebinder of the composition. Cork is highly frictional and it has beenfound that frequently the composition freezes in the extrusion tube withresulting damage to the tube or considerable time consumed in removingthe tube from the device and removing such composition from the tube.Many cork compositions can be extruded for short periods but it is verydifficult to formulate a satisfactory composition which can be extrudedcontinuously over long periods of time. Likewise, it has been foundthat, due to the highly frictional qualities of the cork particles, themass in the center of the tube exhibits a tendency to flow to a greaterextent than those portions of the composition adjacent the walls of thetube so that the edges of the extruded product are compacted to aconsiderably greater extent than its central portion. This results in aproduct of uneven density which is highly undesirable andunsatisfactory. To eliminate to a considerable extent the disadvantagesdiscussed above, it has been proposed to add various lubricants to thecork composition in order to decrease its frictional characteristicsthus aiding in extrusion. Various lubricantshave been proposed but noneof them has been highly satisfactory for in most cases they penetratethe cork particles which require the use of an excessive amount oflubricant thus increasing considerably the cost of the composition anddecreasing its quality, for large amounts of lubricant aflect the binderso that it fails to bind the particles securely to one another.

The chief object of my invention is to provide an improved corkcomposition capable of extrusion. An object of my invention is toprovide a novel and useful lubricant for cork compositions. A furtherobject is to provide an extrudable cork composition containing a lubri-7 Claims. (Cl. 26017.4)

cant. A still further object is to provide an extrudable corkcomposition containing a lubricant which includes a bodying agent toprevent substantial penetration of the lubricant into the corkparticles. Other objects of my invention will be apparent from thefollowing description.

The cork composition of my invention comprises cork particles, a bindertherefor, preferably, capable of being set by heat, and a lubricant toaid in the extrusion of the mass. The lubricant is composed of a mixtureof hydrogenated semi-drying oils, such as hydrogenated cottonseed oil,and a bodying agent to retard or to prevent penetration of thecottonseed oil into the cork particles by increasing the viscositythereof. Preferably, the lubricant is composed of a mixture ofhydrogenated cottonseed oils, one oil being hydrogenated to aconsiderably greater extent than the other and having a higher meltingpoint. I have found a hydrogenated cottonseed oil having a melting pointof about 98 F. and a more highly hydrogenated cottonseed oil, a wax-likeproduct, having a melting point of about 140 F., form a satisfactorymixture. To such mixture is added a bodying agent which is used toincrease the viscosity of the mixture. The preferred bodying agent is amethacrylate resin, which is referred to hereinafter as resin A, andwhich I believe is a polymerized compound, produced by copolymerizing amixture of n-butyl methacrylate and isobutyl methacrylate, having amolecular weight of at least 10,000 and which is thermoplastic andsoluble in the hydrogenated semi-drying oil. Polymethyl methacrylate,polypropyl methacrylate, or similar polymers having a molecular weightof at least 10,000 may be used in place of the preferred resin withsatisfactory results. A suitable lubricant may be formulated as follows,all proportions being given by weight.

Parts Hydrogenated cottonseed oil (M. P.

140 F.) 30 to Hydrogenated cottonseed oil (M. P.

98 F.) 20 to 50 Methacrylate resin (resin A above).. 6 to 20 In thepreparation of the lubricant, the hydrogenated cottonseed oil (M. P. 98F.) is melted and the hydrogenated cottonseed oil (M. P. F.) addedthereto, melted and thoroughly mixed. When the temperature is at 260 F.,the methacrylate resin A is added. While constantly stirring themixture, the temperature is raised to 290 -300 F. and in ten to twentyminutes, the batch is in solution and ready to be added to the corkparticles for use as a lubricant. I show below various specificluoricants formulated for use:

I have found for most satisfactory results the amount of methacrylateresin included in the lubricant should fall within the range of to 12 /2of the total weight of the lubricant. While larger or smaller amounts ofmethacrylate resin, that is, within the limits of 6% to based on theweight of the cottonseed oils, may be used, for most satisfactoryresults the amount of resin used should fall within the range of 10% toli /2% of the total weight of the lubricant.

The lubricant prepared as above may be included with any of the corkcompositions customarily prepared for extrusion. In such compositions,the binder is usually set by heat and I have shown below a. number ofsatisfactory binders for extrudable compositions:

The catalyst is composed of water 20%, sodium bodying agent retains thelubricant on the particles as a coating and thus enables it to performits required function. Generally speaking, the majority of highmolecular weight resins may be used as bodying agents for the abovedescribed lubricant but those described above I have found preferableand available on the open market.

If desired, the extruded products formed from the above compositions mayreceive further .treatment at elevated temperatures to increase the setof the binder. Such treatment aids considerably in overcoming low binderset when extrusion is carried on at low temperatures or if large amountsof lubricant be used.

My invention provides an improved cork composition which may be extrudedand which is formulated to permit the extrusion device to be operatedcontinuously for long periods of time hydroxide 15%, and glycerine 65%.To form the Per cent Per cent Gelatine 27 2o Glycerine 33 25 Water InExample 1, approximately 6.5 parts by without requiring stoppage orshut-downs in order to eliminate composition jammed in the extrusiontubes. I provide a lubricant for extrudable cork compositions which ishighly satisfactory and economical.

While I have described certain preferred embodiments of my invention, itwill be understood my invention is not limited thereto since it may beotherwise embodied within the scope of the following claims.

I claim:

1. An extrudable cork composition which comprises cork particles, abinder capable of being set by heat, a mixture of hydrogenatedcottonseed oils in which one oil has a melting point of about 98 F. andanother has a melting point of about 140 F., and butyl methacrylateresin having a molecular weight above 10,000.

2. An extrudable cork composition mix which comprises a mass of corkparticles, a binder therefor, and a lubricant coating the cork particleswithout substantial penetration into the body thereof, said lubricantincluding a mixture of hydrogenated cottonseed oils in which one oil hasa melting point of about 98 F. and another 5 has a melting point ofabout 140 F., and a bodyweight of such binder may be mixed with 83 parts50 lubricant be included and that the softening 60 point of thelubricant must be lower than the temperature of extrusion. By softeningpoint or melting point I mean a temperature at which the lubricant issoft enough to flow. Generally be low enough to afford fluidity, a largeportion of the lubricant is absorbed by the cork particles. I have foundthat a bodying agent as described above increases the viscosity of thelubricant and is of a molecular size suiilciently great to retard orprevent penetration of the lubricant into the cork particles. Theefficacy of the lubricant may be due to its viscosity or to the largemolecular size of the bodying agent or to a combination of both factors.In any event. the addition of the ing agent for the oils consistingessentially of a thermoplastic methacrylate resin having a molecularweight above 10,000 selected from the group consisting of poiybutylmethacrylate, polymethyl methacrylate, and polypropyl methacrylate.

3. An extrudable cork composition mix which comprises a mass of corkparticles, a binder therefor, and a lubricant coating the cork particleswithout substantial penetration into the body thereof, said lubricantincluding a mixture of hydrogenated cottonseed oils in which one oil hasa melting point of about 98 F. and another has a melting point of about140 F., and a bodying agent for the oils consisting essentially of athermoplastic methacrylate resin having a molecular weight above 10,000selected from the group consisting of polybutyl methacrylate, polymethylmethacrylate, and polypropyl methacrylate, said speaking if thesoftening point of the lubricant 65 oils and resin being inapproximately the following proportions:

Per cent Hydrogenated cottonseed oil (M. P.

98 F.) 30 to '70 Hydrogenated cottonseed oil (M. P.

F.) 20 to 50 Methacrylate resin 6 to 20 4. An extrudable corkcomposition mix which comprises cork particles, a binder therefor, and amixture of hydrogenated cottonseed oils in which one oil has a meltingpoint of about 98 F. and another has a melting point of about 140 F..said last named oil being hydrogenated to a considerably greater extentthan the first named oil. and butyl methacrylate resin having amolecular weight above 10,000.

5 An extrudable cork composition mix which comprises a mass of corkparticles, a binder therefor, and a lubricant coating the cork particleswithout substantial penetration into the body thereof, said lubricantincluding a mixture of hydrogenated cottonseed oils in which one oil hasa melting point of about 98 F. and another has a melting point of about140 F., and a thermoplastic methacrylate resin bodying agent for theoils having a molecular weight above 10,000 and consisting essentiallyof a polymerization product of esters from methacrylic acid and normalbutyl and isobutyl alcohol.

6. An extrudable cork composition mix which comprises a mass of corkparticles, a binder therefor, and a lubricant coating the cork particleswithout substantial penetration into the body thereof, said lubricantincluding a mixture of hydrogenated cottonseed oils in which one oil hasa melting point of about 98 F. and another '7. An extrudable corkcomposition mix which comprises a mass of cork particles, a bindertherefor, and a lubricant coating the cork particles without substantialpenetration into the body thereof, said lubricant including a mixture ofhydrogenated cottonseed oils in which one oil has a melting point ofabout 98 F. and another has a melting point of about F., and athermoplastic polypropyl methacrylate resin bodying agent for the oilshaving a molecular weight above 10,000.

VICTOR A. NAVIKAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,050,272 Canning Aug. 11, 19362,082,278 Ferguson June 1, 1937 2,204,517 Strain June 11, 1940 2,273,780Dittmar Feb. 17, 1942 2,365,508 Austin Dec. 19, 1944 FOREIGN PATENTSNumber Country Date 416,412 Great Britain Sept. 10, 1934

2. AN EXTRUDABLE CORK COMPOSITION MIX WHICH COMPRISES A MASS OF CORKPARTICLES, A BINDER THEREFOR, AND A LUBRICANT COATING THE CORK PARTICLESWITHOUT SUBSTANTIAL PENETRATION INTO THE BODY THEREOF, SAID LUBRICANTINCLUDING A MIXTURE OF HYDROGENATED COTTONSEED OILS IN WHICH ONE OIL HASA MELTING POINT OF ABOUT 98*F. AND ANOTHER HAS A MELTING POINT OF ABOUT140*F. AND A BODYING AGENT FOR THE OILS CONSISTING ESSENTIALLY OF ATHERMOPLASTIC METHACRYLATE RESIN HAVING A MOLECULAR WEIGHT ABOVE 10,000SELECTED FROM THE GROUP CONSISTING OF POLYBUTYL METHACRYLATE, POLYMETHYLMETHACRYLATE, AND POLYPROPYL METHACRYLATE.